/ Dictionary / Index S subbasement: Meaning and Definition of Find definitions for: sub•base•ment Pronunciation: (sub'bās"munt), [key] — n. a basement or one of a series of basements below the main basement of a building. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. subbase subbing Related Content Daily Word Quiz: neologism Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language